private void readContacts(){

        Cursor cursor =null;
        try {

            cursor = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI,null,null,null,null);
            if(cursor  != null){

                while(cursor.moveToNext()){


                    String displayName = cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
                    String number      = cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
                    dataList.add(displayName + "\n" + number);

                }

                adapter.notifyDataSetChanged();
            }
        }catch (Exception e){

            e.printStackTrace();
        }finally{

            if(cursor != null){

                cursor.close();
            }
        }
    }
	
	
	 <uses-permission android:name="android.permission.READ_CONTACTS"/>